Centrosome Structure, Function and Duplication

描述（由申请人提供）：在拟议的研究中解决的核心问题是中心体如何组装，它如何在每个细胞周期中复制一次，以及如何扩展细胞器的“部件列表”以全面了解其工作原理。中心体形成微管，并帮助组织这些微管形成有用的阵列，包括有丝分裂纺锤体和纤毛。中心体是动物细胞中主要的微管组织中心，在细胞周期开始时以单个拷贝的形式存在。中心体在S期复制，产生的两个中心体帮助组织有丝分裂纺锤体的两极。在过去的十年里，我的实验室和其他人的工作已经确定了参与微管成核的分子，中心体复制的中央调节器，参与复制的重要结构蛋白，以及控制中心体数量和连接中心体和细胞周期的控制机制。由于在中心体异常和癌症的发展之间建立了一种相关性，对中心体的兴趣最近有所增长。癌细胞通常有额外的中心体，这可能是导致这种疾病的基因组不稳定和快速进化特征的原因。提出的实验利用了我们在研究中心体结构、功能和复制的试剂和分析方法方面的优势。我们选择关注动物细胞和提取物的过程，因为它们是与我们了解正常细胞分裂和疾病中人类中心体最相关的系统。我将在本提案中阐述四个具体目标：1)描述分离酶在中心粒脱离中的作用。2)描述Plk4在中心粒形成中的作用3)定义导致gammaTuRC定位到微管成核位点的相互作用。4)在MTEC纤毛发生数据集中识别和表征新的中心粒和中心体成分。公共卫生相关性：中心体是细胞的一个组成部分，位于纤维网络（微管）的中心，在细胞内执行工作。中心体在每个细胞中只存在一个拷贝它和染色体一起复制每个细胞周期。中心体复制控制失败会导致染色体分离问题，并与癌症有关。

DESCRIPTION (provided by applicant): The central problems addressed in the proposed research are how the centrosome is assembled, how it duplicates once per cell cycle, and how the "parts list" for the organelle can be expanded to generate a complete understanding of how it works. The centrosome nucleates microtubules and helps to organize those microtubules to create useful arrays, including the mitotic spindle and the cilium. The centrosome is the major microtubule organizing center in animal cells, and is present in a single copy at the beginning of the cell cycle. The centrosome duplicates in S phase, and the two resulting centrosomes help to organize the two poles of the mitotic spindle. Work from my lab and others over the last ten years has identified molecules involved in microtubule nucleation, the central regulators of centrosome duplication, important structural proteins involved in duplication, and control mechanisms that control centrosome number and link the centrosome and the cell cycle. Interest in the centrosome has grown recently because of the role of a correlation has been established between centrosome abnormalities and the development of cancer. Cancer cells often have extra centrosomes, which is likely to contribute to the genomic instability and rapid evolution characteristic of this disease. The proposed experiments make use of the strengths that we have developed in reagents and assays for studying centrosome structure, function and duplication. We have chosen to focus on the process in animal cells and extracts as they are the systems most relevant to our desire to understand the human centrosome in normal cell division, and in disease. I will address four specific aims in this proposal: 1) Characterize the role of separase in centriole disengagement. 2) Characterize the role of Plk4 in centriole formation 3) Define the interactions responsible for localization of the gammaTuRC to sites of microtubule nucleation. 4) Identify and characterize new centriole and centrosome components in MTEC ciliogenesis dataset PUBLIC HEALTH RELEVANCE: The centrosome is a component of the cell that sits at the center of a network of fibers, microtubules, that perform work within the cell. The centrosome is present in exactly one copy per cell and it duplicates every cell cycle, along with the chromosomes. Failure to control centrosome duplication leads to problems with separation of chromosomes and is associated with cancer.